jenswilly.dk


LPC ARM USB CDC

2. August 2012 12:55 by Jens Willy Johannsen
Categories: ARM

…the unabbreviated title would be very long :)

Anywho, this is just a quick post to link to my Github project which contains firmware for using an LPC11U24 as a USB "communications device" – i.e. a serial port.

At the moment, it simply writes input from the serial interface to the USB and vice versa. So you can connect the device to a computer with both USB and a serial cable (I use a serial-to-USB cable since I have no "real" serial ports on my MacBook Pro) and then open terminal connections to both interfaces (using "screen /dev/tty.xxx 9600" or something similar) and everything typed in one window gets written in the other window.
There's probably a couple of debugging messages as well.

The project is based on NXP's example code found here: http://www.lpcware.com/content/nxpfile/usb-rom-driver-examples-using-lpcxpresso-lpc11uxx and compiles with the Yagarto toolchain.

Why?

Why would I want to do USB connectivity by way of CDC instead of e.g. HID? Because implementing HID functionality in Mac OS X applications is a pain in the ass, that's why.
Serial port connectivity, however, is so very much simpler. Especially if you use the excellent ORSSerialPort library.

Where?

Right here: https://github.com/jenswilly/LPC11U24-USBCDC

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